High and Low Key Lighting

High key lighting is a method of lighting film that found its place in the workplace due to its compatibility with three point lighting. This lighting method uses light to create a low amount of contrast between the darker and brighter parts of a certain shot. High key lighting is a versatile method as it can be used with a number of shots in order to achieve many goals. The main goal is to avoid shadows. Due to the lack of shadows, high key lighting is used for more jovial scenes that belong is more 'upbeat' genres such as comedies and musicals.

Low key lighting is the opposite and is therefore used in much harder hitting and gritty films that belong in genres such as horror and noir. The goal of low key is to bring about many shadows and focus light on certain areas of shots in order to highlight something. Low key lighting can be used to create eery and suspenceful moments that have the audience on edge.

The way that these two lighting can be used in the same film is to convey the atomsphere that the plot is presented with. For example, a scene incorporating high key lighting can give the sense that everything is normal and the audience can be feel safe due to there being nothing to suspect. In contrast, a low key shot gives a much more ominous feeling, even if it is used on the same character and scene as previously seen in a high key shot. Here is an example taken from Alfred Hitchcock's 1954 thriller 'Rear Window'.

Source: Film Blog 'Film 110' - Lighting